Field of the Invention
The present invention relates to an internal combustion engine in which a combustion pressure sensor incorporated glow plug is mounted to one or more of a plurality of cylinders of an engine body, and a sensor nonincorporated glow plug having no pressure sensor is mounted to each of the remaining cylinders.
Background Art
A known combustion pressure sensor incorporated glow plug is a glow plug which assists in start-up of an internal combustion engine such as a diesel engine and into which a pressure sensor is incorporated for detecting combustion pressure in a combustion chamber of the internal combustion engine (refer to, for example, Patent Document 1). In the combustion pressure sensor incorporated glow plug, a heater is disposed within a housing in an axially movable condition. An axial movement of the heater resulting from variation in combustion pressure is transmitted to a pressure sensor, thereby detecting combustion pressure within the combustion chamber of the internal combustion engine.
The internal combustion engine (engine body) has a plurality of cylinders, such as four or six cylinders. In view of costs, etc., such a combustion pressure sensor incorporated glow plug may be used in the internal combustion engine such that the combustion pressure sensor incorporated glow plug is mounted to one or more of a plurality of cylinders, whereas an ordinary glow plug (hereinafter, may be called a sensor nonincorporated glow plug) having no pressure sensor (combustion pressure sensor) is mounted to each of the remaining cylinders.